An electronics module generally comprises a member mounted on a support by means of a joint that guarantees both mechanical and electrical connection of the member on the support.
Such electronics modules need to be adapted to withstand relatively high thermal stresses, the local temperature inside the motor vehicle, in particular in the engine compartment, being capable of reaching values much greater than 150° C.
In particular, the material forming the joint between the support and the member needs to have a melting point greater than the maximum temperatures to which the electronics module is subjected so as to avoid the support and the member coming apart while in use.
For example, a material essentially comprising silver is well suited since the melting point of silver is greater than 900° C.
In order to make such a joint, it is known in the state of the art, and in particular from US 2005/0247760, to implement a method of assembling an electronic component on a support by sintering a mass that comprises a mixture of conductive powder and of solvent.
During that assembly method, the solvent is removed from the mass by heating the mass so as to cause the solvent to evaporate.
Thereafter, the mass of powder is placed on a film that forms a temporary support and the chip is put into place on the mass. Thereafter, the chip and the mass are heated and a first compression force is applied thereto. The action of heat and the first compression force pre-sinters the powder mass and bonds the mass with the chip.
After separating the mass that is bonded to the chip from the temporary support, the mass bonded to the chip is placed on a final support. Thereafter, heat is applied, as is a second compression force urging the chip against the mass and the final support. The action of the heat and of the second compression force causes the powder mass to sinter and bonds the mass to the final support.
Thus, during that assembly method, the chip is subjected to two compression forces of relatively high magnitude, which runs the risk of damaging the chip.
Furthermore, because a compression force is applied twice urging the chip against the mass and only once urging the mass against the support, the mass may adhere to the chip more strongly than it does to the support. That unbalance can give rise to stresses within the powder mass, thereby weakening the bond between the chip and the support.